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The proximity of rail corridors to livestock production enterprises poses potential risks to welfare and production. The association between these factors and production have been extensively investigated. This review aims to assess the potential impact on the basis of existing data in a livestock production context. Due to expansion of freight rail networks through agricultural land, there is a need to investigate potential impacts of rail (including train and track) noise, vibration and visual disturbance on the physiology and behaviour of the livestock and subsequent production traits. Additionally, the factors influencing the impact on animals were characterised broadly as noise, vibration, and visual and spatial disturbance. This information was used to develop conceptual frameworks around the contribution of rail impact on allostatic load, animal welfare and production. Placing rail noise in the context of other, known, noise impacts showed that proximity to the rail line will determine the impact of noise on the behaviour and physiology of the animal. Thresholds for noise levels should be determined on the basis of known noise thresholds, taking into account the impact of noise on allostatic load. Further research is recommended to investigate the behavioural, physiological and production impacts on livestock from proximity to rail corridors. Current literature suggests that the allostatic load will vary depending on the proximity of the animal to the source of stimulus, the type, size or level of stimuli, habituation and the individual animal variation in response to the stimuli. [ABSTRACT FROM AUTHOR]

Context: Cassava bagasse is readily available in tropical countries as an energy source for ruminant diets, but previous research has shown low cattle performance at high inclusion rates. Aims: The nature of the dose–response relationship between increasing inclusion rate of cassava (Manihot esculenta Crantz) bagasse (CB), substituting for protein meals in diets of fattening cattle, was used to evaluate the reduced animal performance at high inclusion rates. Methods: Thirty growing Madura (Bos indicus × javanicus) bulls were fed concentrate-based diets with five levels of CB inclusion at 20 g dry matter (DM)/kg liveweight and elephant grass (Pennesetum purpureum) separately at 5 g DM/kg liveweight. The five tested CB inclusion rates into the offered diet were 30, 40, 50, 60 and 70% of total dry matter. Lines of best fit were used to describe the relationships between animal performance and CB inclusion rate. Key results: Intake of dry matter and concentrate both demonstrated a quadratic relationship with increasing CB inclusion, both maximised at 46–47% CB inclusion in the offered diet or a CB intake of ~9.7 g CB/kg liveweight. Liveweight gain and change in body condition score both demonstrated a quadratic dose–response relationship with increasing CB inclusion, with maximal performance achieved at 34–38% inclusion of CB. Although protein content at the highest level of CB inclusion was low (68 g/kg DM), modelling of predicted liveweight gain indicated that this was most constrained by energy intake (as a function of concentrate intake), rather than crude protein. Conclusions: Inclusion of CB up to ~45% of the diet, substituting for protein meals, does not improve, but has no detrimental effect, on liveweight gain. The plateauing of CB intake above 50% inclusion in in the offered diet suggests that cattle were eating to a maximal CB intake. Several hypotheses for reduced intake of concentrate at high levels of CB inclusion were proposed, including low protein content and hydrogen cyanide content of the CB, none of which satisfactorily explained why intake of concentrate was depressed above 50% CB inclusion of the diet on offer. Implications: Rations should be formulated to contain no more than 50% CB for maximal cattle performance. Further research is required to understand the causes of depressed intake at high inclusion rates of CB. Cassava bagasse is a by-product feedstuff with potential as a ruminant feed in tropical environments, but there is poor understanding regarding production responses from its inclusion in cattle diets. We found that when cassava bagasse inclusion in a concentrate mix was increased, cattle intake of the concentrate mix increased, but in a curvilinear fashion. We suggest that cattle will eat no more than a maximal limit of cassava bagasse intake, although the reasons why are not clear. [ABSTRACT FROM AUTHOR]